Effects of diabetes mellitus on red cell properties

Abstract

To investigate the possibility that altered red cell characteristics contribute to the development of diabetic vascular complications, hematologic, rheo1ogic and oxygen transport variables were measured in 42 juvenile-onset and maturity-onset diabetics, and in 36 age- and sex-matched controls. Viscosity measurements were performed on plasma, whole blood and washed red cell suspensions, and the filtration rate of dilute erythrocyte suspensions through 3µ pores was timed. Hemoglobin-oxygen affinity, glycosy1ated hemoglobin, 2,3-diphosphog1ycerate and carboxyhemoglobin were also measured. In comparison to controls, all diabetics as a group demonstrated slightly lower mean cell volume, slightly higher whole blood viscosity and increasingly higher levels of red cell suspension viscosity at decreasing shear rates. Red cell filtration values were similar between diabetics and controls who did not smoke but were elevated in the smoking controls, and further increased in the smoking diabetics. P50(7.4) values were 1 mm Hg lower than control values in both the juvenile-onset and adult-onset non-smoking diabetics. No correlations between any of these variables and the presence of vascular disease were apparent. Some thoughts regarding the mechanisms of these findings are offered.